package com.mmall.service.Impl;

import com.google.common.collect.Lists;
import com.google.common.collect.Sets;
import com.mmall.common.ServerResponse;
import com.mmall.dao.CategoryMapper;
import com.mmall.pojo.Category;
import com.mmall.service.ICategoryService;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.util.CollectionUtils;

import javax.servlet.http.HttpSession;
import java.util.List;
import java.util.Set;

/**
 * @Author 侯俊杰
 * @Date 2017/11/2
 * @Time 22:22
 **/

@Service("iCategoryService")
public class CategoryServiceImpl implements ICategoryService
{

    private Logger logger = LoggerFactory.getLogger(CategoryServiceImpl.class);
    @Autowired
    private CategoryMapper categoryMapper;

    public ServerResponse addCategory(String categoryName,Integer parentId)
    {
        if (parentId == null || StringUtils.isBlank(categoryName))
        {
            return ServerResponse.createByErrorMessage("添加品类参数错误");
        }

        Category category = new Category();
        category.setName(categoryName);
        category.setParentId(parentId);
        category.setStatus(true);//这个分类是可用的

        int rowCount = categoryMapper.insert(category);
        if(rowCount > 0)
        {
            return ServerResponse.createBySuccess("添加品类成功");
        }

        return ServerResponse.createByErrorMessage("添加品类失败");
    }

    public ServerResponse updateCategoryName(Integer categoryId, String categoryName)
    {
        if (categoryId == null || StringUtils.isBlank(categoryName))
        {
            return ServerResponse.createByErrorMessage("更新品类参数错误");
        }
        Category category = new Category();
        category.setId(categoryId);
        category.setName(categoryName);

        int rowCount = categoryMapper.updateByPrimaryKeySelective(category);//有选择性更新
        if(rowCount > 0)
        {
            return ServerResponse.createBySuccess("更新品类名字成功");
        }
        return ServerResponse.createByErrorMessage("更新品类失败");
    }

    public ServerResponse<List<Category>> getChildrenParallelCategory(Integer categoryId)
    {
        List<Category> categoryList = categoryMapper.selectCategoryChildrenByParentId(categoryId);
        if(CollectionUtils.isEmpty(categoryList))
        {
            logger.info("未找到当前分类的子分类");
        }
        return ServerResponse.createBySuccess(categoryList);
    }

    /**
     * 递归查询本节点的id以及孩子节点的id
     * @param categoryId
     * @return
     */
    @Override
    public ServerResponse<List<Integer>> selectCategoryAndChildrenById(Integer categoryId)
    {
        Set<Category> categorySet = Sets.newHashSet();

        //经过findChildCategory递归算法后，categorySet里已经被填充完毕selectCategoryAndChildren
        findChildCategory(categorySet,categoryId);

        List<Integer> categoryList = Lists.newArrayList();
        if(categoryId !=null)
        {
            for(Category categoryItem : categorySet)
            {
                categoryList.add(categoryItem.getId());
            }
        }
        return ServerResponse.createBySuccess(categoryList);
    }

    //用Set里放对象时，为了排重要重写bean类的equals和hashCode方法，这与Set的底层实现有关
    //递归算法算出子节点
    private Set<Category> findChildCategory(Set<Category> categorySet ,Integer categoryId)
    {
        Category category = categoryMapper.selectByPrimaryKey(categoryId);
        if(category!=null)
        {
            categorySet.add(category);
        }
        //查找子节点，递归算法一定要有一个退出的条件

        //Mybatis当返回为List而结果真的为空，List也!=null
        List<Category>categoryList = categoryMapper.selectCategoryChildrenByParentId(categoryId);
        for(Category categoryItem : categoryList)
        {
            findChildCategory(categorySet,categoryItem.getId());
        }
        return categorySet;
    }

}
